From Chapter 1:
"'It requires no effort of the fancy to picture these three men [Shakespeare, Bacon and Raleigh] as lounging in a window of Durham House, puffing the new Indian weed from silver bowls, discussing the highest themes in poetry and science, while gazing on the flower-beds and the river, the darting barges of dame and cavalier, and the distant pavilions of Paris garden and the Globe.'" This is a pure "effort of the fancy" so far as Bacon and Shakespeare are concerned. Shakespeare's absolute silence about tobacco forbids us to assume that he smoked; but of Raleigh the picture may be true enough. The house had, as Aubrey tells us, "a little turret that looked into and over the Thames, and had the prospect which is as pleasant perhaps as any in the world"; and it would be strange indeed if the owner of the noble house did not often smoke a contemplative pipe in the window of that pleasant turret.

From Chapter 8:
More than one writer of recent days has absurdly misrepresented Johnson as a smoker. The author of a book on tobacco published a few years ago wrote—"Dr. Johnson smoked like a furnace"—a grotesquely untrue statement—and "all his friends, Goldsmith, Reynolds, Garrick, were his companions in tobacco-worship." Reynolds, we know—

When they talk'd of their Raphaels, Corregios, and stuff,
He shifted his trumpet, and only took snuff.

Johnson and all his company took snuff, as every one in the fashionable world, and a great many others outside that charmed circle, did; but Johnson did not smoke, and I doubt whether any of the others did.